Propeller.



F. H. LUENSE.

PROPELLER.

APPLlcATloN FILED Nov. to. 1916.

Patented' Apr. 2, 1918.

LLlL

mit? 'l Be it known that I, FREDERICK H. LUENBE,

a subject of the Emperor of Germany, havmg announced my intention ofbecomin a citizen of the United States of America, `and a resident ofSta leton, Staten Island, Richmond county, an State of New York, haveinvented certain new and useful Imrovements in Prsellers, of which thefolowing is a spec' cation, reference being had to the accompanying in apart thereof.

y invention relates to methods or proc'- drawings, formesses of coatingor finishing articles and has special reference to such as ,areapplicableto aeril propellers and otherv devices made of 'c vantagesover coatings produce adapted to coperate in the pro fully dried toavoid b ut when propellers @ne object of my invention is to providemetallic coating is produced which is ve intimately-united with thearticle itself.

Another object is to provide a process of coatin tion o definite stepswhic are articularly uction of a e metallic coating possessin .many adofthe ste taken alone. Prope ers for aerial navigation are relativelylargeand operate at highsieeds and they are of course necessarily ight andstrong. In order to fulfil these conditions, they are usually 'made ofwood andare built up in sections which are very carefully united.Furthermore, the wood is very carewarping and tw of this nature arersubjected to adverse vatmospheric conditions such as are encountered,for example, in

tro ical countries, they rapidly deteriorate an in many instances havebeen known to go to pieces.

he process of myinvention is particularly adapted for the `purpose ofproviding a coatin which shall hermetically seal the ropeer andovercomethe above-named 'iiiculties. f

In order that my invention may be thoroughly understood I will nowproceedto descri the same in the following specification, and then pointout the novel features thereof in appended claims.

Referring to the drawings;

Figure 1 is an end elevation of a propeller Bpction of Lettera une,

Appliwtlon med November 10,1918. l el -w A To all 'whom it may concern.'

" with molten metalwhich shall com rise a combina' by eitherelectrolytically deposit;

raten ai. ai.l o. rac..

which may be provided with a coating applied'in accordance with theprocess of myinvention. Fig. 2 is a side elevation partly in section ofa propeller and other devices and illustrates one of the steps 4of thecoatin process in which the propeller is 'raye in a finely divide form.The next ste v of the processis illustrated 1n Fig. 3-whic shows'thepropellerin an electrolyticbath.

Fig. 4 illustrates on a very lar e scale, the form of the surface as rstproduced by the process steps of Figs. 2 and 3, and Fig. 5 illustratesthe result ofthe -next step of the process, viz., that of bug thesurface.

It will of course be understood that my process is by pro ellers or anyparticular class of articles. e propeller illustrated is formed oflaminationslO, 11 and 12 of wood, which are securely glued together tomake a le piece and are'tlen shaped to the dd propeller form. The woodis finished smooth to the desired shape but no filler ror finish isapplied before it is subjected tothe first step of the coating process.

This process with which my resent invention is particularly concernfirst' spraying the prtpeller with molten metal in a finely divide form.

This maybe accomplished by the use of any well known apparatus suchI asthat designated 2O in Fig. 2.v In this arrangeno means limited to'wooden sa v ment compressed air or other 4suitable gas is e utilizedfor atomizing molten metal and of the propeller.

The metal utilized may be zinc, bronze, copper or aluminum, or someother suitable material. As the tine particlesv of metal strike thesurface of the wood with high velocity, the sink into the pores of thewood and a here very tenaciously thereto. By this reason a metalliccoating is formed in particularly intimate connection with the surfaceof the propeller. This coating forms an excellent foundation forthe'next step of the process which consists in subjecting the very thinlcoated propeller to the action of ain electro ytic bath as shown in Fig.3, to or, in other words, to electroplate the metallic `coating alreadyapplied by the step illustrated in Fig. 2.

As shown in Fig. 3, 22 designates a container, having a metallic lining23 which is connected by a; conductor 24 to the positive side of a sup1y circuit. The4 propeller is immersed in t e liquid bath 25 within thecontainer and is connected by conductors 26 -produce a substantiallyuniform coatmg with a smooth outer surface which has a ver low airresistance.

oodcn articles or articles of other materials may be treated in themanner above described within the spirit and scope of my invention.

what I claim is.:y 1. The fprocess of coating wood that consists inorcibly spraying the wood with molten metal in a finely divided form toinject the metal into the surface of'the wood and to seal the woodagainst moisture, and

then immersing the coated Wood in an electrolytic bath andelectrolytically depositing additional metal on the coated wood.

2. The rocess of coating wood that consists in orcibly spraying the woodwith molten metal in a finely divided form to inject the metal into thesurface of the wood and to seal the wood against moisture, thenimmersing the coated wood in an electrolytic bath and electrolytcallydepositin additional. metal on the coated wood, and urnishng orpolishing the surface to uniformly distribute the metal in the coating.

ln witness whereof, I have hereunto set my hand this 2 day of November,1916.

FREDERlCK HUGO LUENSE.'

